1. Field of the Invention
The present invention is related to processing digital video information captured by a digital video camera in an MPEG information processing system.
2. Related Art
Recently, digital video cameras (e.g., camcorders) have become popular in the consumer market. Most consumers who have digital video cameras want to output the digital video information using a high quality output device. This can be done using cables hooking audio and video outputs from the camera either into inputs of a television or a video playback device (e.g., a VHS, DVD player, etc.). An increasing number of consumers want to play their captured digital camera information back through set-top boxes.
The digital set-top box (e.g., a high bandwidth data pipe) is ideally positioned as the hub of a networked home, acting as the “Home Gateway,” enabling devices in the home to link with each other and the outside world. It is a consumer device increasingly becoming exclusively used to access online interactive services. As a result of its core capability in the delivery of digital television, its consumer interface is also attractive and easy to use. Unfortunately, the set-top boxes are typically only configured to process and output MPEG signals, and not digital video information, such as DV25, DV50, or similar signals. MPEG (The Moving Picture Experts Group) has developed compression systems used for video data. For example, digital video disc (DVD) movies, high definition TV (HDTV) broadcasts, and digital spread spectrum (DSS) satellite systems use MPEG compression to fit video and movie data into smaller spaces. The MPEG compression system includes a subsystem to compress sound, called MPEG Audio Layer-3 (e.g., MP3)
One example of digital video camera uses DV25 format for generating digital video information (e.g., DV_FRAME and DV_DATA signals). The bit rate for the video stream can be 25 Megabits per second (Mbps). Typically, these digital video cameras can transmit the digital video information via a transceiver (e.g., an IEEE 1394 transceiver). Some of these cameras can function using IEC 61833-1, 61833-2, 61834-1, and/or 61834-2 standards. Other example cameras can use DV50 or other known formats.
MPEG system clock reference (SCR), program clock reference (PCR), presentation time stamp (PTS), and decode time stamp (DTS) are described in detail in Annex D of ISO/IEC13818-1. In summary, the clock references are used to recover the system clock and the time stamps are used to indicate when to decode and display elements relative to the recovered system clock.
The clock references and timestamps are required for correct operation of an MPEG system, where: (a) a rate of decoding must be correct to avoid buffer overflow/underflow and (b) audio and video must be properly synchronized at the display. MPEG timestamps are standard and robust. Systems have been built to expect MPEG timestamps, and exploit timestamps for other purposes. For example, some video recorder systems use MPEG timestamps to implement trick modes, such as fast forward and reverse. The term “timestamp” is used throughout to refer to at least SCR, PCR, PTS, and DTS values, and any other values that may be known to skilled artisans.
One reason the digital video information cannot be played back through set-top boxes is because MPEG signals generally include time stamps that are used for playback. The time stamps are used to tell a device when to start outputting (e.g., displaying) a decoded signal. Time stamps are critical to the operation of the set-top boxes. Unfortunately, digital video signals, such as DV25, DV50, or other similar signals, do not include time stamps. Thus, consumers who capture digital video information with their digital cameras cannot play the information using set-top boxes.
Therefore, what is needed is a system and method that allows a set-top box to process and output digital camera information, such as DV25, DV50, or other similar information.